预制桥墩承插式连接轴压性能分析

Performance of Socket Connections for Precast Bridge Columns Subjected to Axial Load

为研究预制桥墩承插式连接在轴压作用下的力学性能,通过非线性三维数值模拟,确定了测试承插式连接轴压性能的合理模型设计方案,研究了墩柱承插深度、墩柱界面构造以及灌浆料强度对轴压性能的影响规律。研究结果表明:基于表面接触算法的ABAQUS有限元数值模型能较好地模拟承插式连接在轴压荷载下的力学行为;采用圆形底座与外包约束钢管的试件设计方案可避免因应力集中产生的底座开裂现象,有利于充分测试承插式连接的轴压性能;增加墩柱承插深度将提升承插式连接的轴压承载力,且承载力提升与承插深度增加呈线性关系,但承插深度对连接侧剪力强度的影响较小;采用波纹、键齿、糙化三类墩柱界面构造的承插式连接轴压性能相似;灌浆料抗压强度由40 MPa提升至80 MPa,承插式连接轴压承载力仅提升11.4%。

To investigate the performance of socket connections for precast columns subjected to axial load, through the nonlinear three-dimensional numerical approach, this paper introduced the details of the designed models and studied the effects of column embedment length, column surface texture, and grout strength on the connection performance. The results indicated that:the ABAQUS numerical model with the surface contact algorithm adequately captured the structural behavior of the socket connections;the specimen with round foundation and confining steel tubes was adequate to fully exercise the axial performance of socket connection;increasing of column embedment length increased the strength of the socket connection in a linear relationship, whereas it had negligible effect on the side shear stress of the socket connection;the socket connections with different column surface texture exhibited comparable axial performance;the connection strength was increased by only 11.4% with increasing the compressive strength of grout from 40 MPa to 80 MPa.